Conor McGregor responded to praise and admiration from Floyd Mayweather with, well, some not so kind words. (AP)

Promotion for the upcoming UFC 229 megafight between Conor McGregor and Khabib Nurmagomedov is officially rolling.

And, of course, it’s all calm and reasonable.

Floyd Mayweather sings praises of Conor McGregor

TMZ caught up with Floyd Mayweather on Monday in Atlantic City to get his thoughts on the Oct. 6 clash for the lightweight championship. Mayweather, who faced McGregor in the boxing ring last year, had nothing but kind words for his former opponent and warned Khabib to be ready for a fight.

“I take my hat off to Conor McGregor,” Mayweather said. “A hell of a fighter. …“Conor’s not gonna back down and he’s not a scared fighter at all, win, lose or draw. Conor’s gonna come to fight.”

Mayweather even invited McGregor to train at his gym instead of UFC facilities ahead of the Las Vegas fight. Of course, that seems more a plug than an act of altruism toward McGregor, but it’s a nice offer nonetheless.

McGregor’s bizarre response

McGregor responded to the interview on Twitter Tuesday. The language he used was not friendly.

Fuck the Mayweathers, except Senior and Roger. There is no peace here kid. Step up or step down.

Maybe McGregor was mad that Mayweather wouldn’t pick him in the fight.

“I don’t really have a prediction because I’ve never seen the guy fight that’s facing Conor McGregor — from what I know he’s a hell of a guy that’s on the ground — hell of a grappler — and he can wrestle,” Mayweather said.